Should I Deinterlace?

[toadatrix]

I want to convert a 720x480 DV interlaced source to a 320x240 progressive mode video file. Should I deinterlace the source when doing this conversion or is that unnecessary because going from 720x480 to 320x240 will automatically remove one of the interlaced fields? Please explain as I have never understood whether deinterlacing is necessary when files are downsized.

[Darkbird]

You should probably aim for 352x240 to keep the proper aspect ratio (4:3). Unless you you want to set the aspect ratio at 1:1 for square pixels on a computer display.

I believe mpeg1 video is always progressive encoded. I'll let others advise on whether deinterlacing is necessary for the conversion. (I work mostly with mpeg2 for DVD)

<font size=-1>[ This Message was edited by: Darkbird on 2001-08-02 06:40:33 ]</font>

[tacosalad]

It's almost always necessary to deinterlace DV when reducing its size, or else you'll end up with double-images. This is because every interlaced field is a perfect independent "snapshot", so anything that combines fields (like a bicubic or bilinear resize) just tends to yield a double-image.

You didn't say what you plan to do with the finished footage. If you intend to record it onto VCD, consider keeping the footage 480-line interlaced and try using SVCD. Most users complain that motion looks rough when transferring DV to VCD.

The best advice, though, is to try a few samples for yourself, and then to choose what you think yields the best results for your footage.